aircraft remover + pressure washer!!!
i am doing this now to one of my boats, it's easily stripping off 5+ layers of paint with little to no effort from my end. just brush it on, wait a couple minutes, then pressure wash it off. done. i did about 1/6 of the interior of a 14' boat in 10 minutes today just to test the process. i expect to get the whole boat stripped tomorrow morning.
i don't like the idea of removing the paint from an aluminum boat by sanding or wire brushing since you inevitably also remove a small portion of the hull. stripping with aircraft remover just takes off the paint and leaves you with a surface that pretty much looks like new.